HDMI oddness


Well-Known Member
We recently got a new Sony TV which replaced our 11 year old Panasonic. Connections wise it was a drop-in, so the arrangement is:
RF side - Humax 1010S with own feed from satellite dish; two FOX-T2 fed from the terrestrial aerial via a splitter, with onward feed to the TV from one of the box's RF output.
HDMI side - the three boxes all feed into an electronic switcher with the output of that going to the TV. (There is a Blu-ray player too but that has its own connection to a separate port on the TV.)
I noticed while researching the TV that one review said they had been unable to get their Sony TV (it wasn't this exact model) to work with their Humax box and I think there have been reports on here about odd HDMI handshake issues, so I was prepared for a possible problem. However, it all worked just fine.
Until ...

As this is now a 'smart' TV with built-in freeview play, the other day I decided to try and split the RF three ways, so the TV wasn't dependent on the FOX for its signal. I bought a 3-way coax splitter, turned off the power to the TV and boxes, and removed the 2-way splitter. It was at this stage I discovered that the new splitter had all the connections the opposite gender to my system.
So I replaced the 2-way one, pushed everything back into place, powered up and started checking everything was OK (the three Humax boxes are in a tight space, so doing anything physical to them invariably disturbs all the connections to everything).
At this point I discovered that the 1010S worked fine, but neither FOX box did. As they booted up the Humax start screen displayed on the TV, but on going to actual content the screen blanked and the TV reported no signal. This was a little disconcerting. I swapped the HDMI leads around on the switch but the result was the same, the older boxes were not delivering programmes. I guessed it was probably a handshake issue, but couldn't think what was different for this to happen now.

Eventually one difference occurred to me. When I changed the TV I didn't turn off the boxes, they were in standby, whereas this time when the TV was powered the boxes were also going through their initial boot cycles. So I killed the power again, isolated the TV, restored the power, waited a few minutes until all the boxes had finished their stuff and gone back to sleep (handily, the lights on the HDMI switch tell you when this has happened), and only then powered the TV, so it could do it's boot cycle.
Success! All working again.

What was going on? I have no idea, but at least now if we have a power cut or the like I know that the TV needs to be 'retarded' to be last to start.